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Selenium speciation analysis of selenium-enriched food sprouts
23-28Views:182In this present study, we prepared selenium-enriched pea and wheat sprouts. During our research we aimed not only to measure the total selenium content of the sprouts but to identify different selenium species.
Scientifical researches show why the analytical examination of different selenium (Se) species is necessary: consumption of all kind of Se-species is useful for a person who suffers in selenium deficit, while there is significant difference between effects of different Se-species on person, in whose body the Se-level is just satisfactory. Biological availability, capitalization, accumulation, toxicity of Se-species are different, but the main difference was manifested in the anti-cancer effect of selenium.
During our research selenium was used in form of sodium selenite and sodium selenate, the concentration of the solutions used for germination was 10 mg dm-3. Control treatment meant germination in distilled water. Total selenium content of sprout samples was measured after microwave digestion by inductively coupled plasma mass spectrometry (ICP-MS). Different extraction solvents were applied during sample preparation in order to separate different Se-species (0.1 M and 0.2 M HCl or 10 mM citric acid buffer). We wanted the following question to be answered: Which extraction solvent resulted the best extraction efficiency? Selenium speciation analysis of sprout sample extracts was performed by high performance liquid chromatography with anion exchange column, detection of selenium species was performed by ICP-MS.
Evaluating our experimental results we have been found that significant amount of selenium of inorganic forms used during germination transformed into organic selenium compounds. There was difference between the amount of Se-species in pea and wheat sprouts and selenium uptake and repartition of selenium species were depended on Se-form used during germination. In addition the chromatogram analysis made us clear as well, that the citric acid solvent proved to be the most effective extraction solvent during sample preparation int he view of organic Se species.
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Optimization of inductively coupled plasma mass spectrometer parameter’s to measuring arsenic and selenium
59-64Views:159In the last decades an increased interest has been evolved about arsenic and selenium. The aim is to understand the environmental, agricultural and biological role of the these elements. In case of arsenic the mayor reasons are the relatively high concentration of arsenic in marine biota (mg kg-1) and the arsenic contaminated drinking waterbases of some Asian countries besides Hungary. The toxicity of higher level selenium content is also known, nevertheless selenium is essential for some biological functions. Considering its esssentiality, in our country the insufficient selenium intake rate couse lack of selenium. Measuring the concentrations of these elements are cruital but not satisfactory information, but the speciation, that is the form of an element presented in a sample is also required.
In both cases the most suitable method to determine concentration is the inductively coupled plasma mass spectrimetry. My objective was to optimase the changeable parameters of the ICP-MS for reaching the lowest (the best) detection limit. For this porpuse I have investigated the effect of parameter change on nett signal intensity and relative signal intensity. With the optimased parameter settings the limit of detection for arsenic and selenium were determined, which are 0,032 ng cm-3 for arsenic, and 0,097 ng cm-3 for
selenium. -
Parameter optimization of an inductively coupled plasma mass spectrometer for measuring arsenic and selenium
81-85Views:143In the last decades, an increased interest has evolved in arsenic and selenium. The aim is to understand the environmental, agricultural and biological roles of these elements. In the case of arsenic, the major reasons are the relatively high concentration of arsenic in marine biota (mg kg-1) and the arsenic contaminated drinking water bases of some Asian countries, as well as Hungary. The toxicity of higher level selenium content is also known; nevertheless, selenium is essential for several biological functions. Considering its essentialness, in our country, the insufficient selenium intake rate causes a lack of selenium. Measuring the concentrations of these elements provides crucial, but unsatisfactory information, as the speciation, i.e. the form of an element presented in a sample is also required.
In both cases, the most suitable method to determine concentration is inductively coupled plasma mass spectrometry (ICP-MS). Our objective was to optimize the variable parameters of the ICP-MS to attain the lowest (the best) detection limit. For this purpose, we investigated the effect of parameter change on net signal intensity and relative signal intensity. With the optimized parameter settings, the limits of detection for arsenic and selenium were determined, which are 0,032 ng dm-3 for arsenic, and 0,097 ng dm-3 for selenium. -
Selenium-speciation experiments from soil samples by accept of ionchromatography-inductively coupled plasma mass spectrometry (IC-ICP-MS) method
106-111Views:129In these days, selenium is one of the most investigated microelements. It has an important proven role in many vital processes. Selenium deficiency can play a role in the contraction of many diseases (e.g. cancer, heart diseases, etc.) and in the aggravation of their clinical aspect directly or indirectly. In this paper, we study the soil samples of an outdoor experiment for the conversion of the inorganic selenium salt that was spread out in different doses. The danger of the wash-out effect was also investigated. Our experiments showed, that most of the inorganic selenite transforms to selenate form during the years, and in this selenate form it moves to the deeper layers of soil.